package com.example.reggie.filter;

import com.alibaba.fastjson.JSON;
import com.example.reggie.common.BaseContext;
import com.example.reggie.common.Result;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 检查用户是否完成登陆
 * 可用jwt令牌改进
 */
@WebFilter(filterName = "loginCheckFilter",urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {

    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        //获取URL
        String requestURI = request.getRequestURI();
        log.info("拦截到的请求{}",requestURI);

        //定义不需要处理的请求路径
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/common/**",
                //对用户登陆操作放行
                "/user/login",
                "/user/sendMsg"
        };

        //判断是否需要处理，如果不需要处理，直接放行
        boolean check = check(urls,requestURI);
        if(check){
            log.info("本次请求{}不需要处理",requestURI);
            filterChain.doFilter(request, response);
            return;
        }

        //判断登陆状态，如果已登陆，直接放行(backend)
        if(request.getSession().getAttribute("employee") != null){
            log.info("用户已登陆，id为{}",request.getSession().getAttribute("employee"));
            Long empId = (Long) request.getSession().getAttribute("employee");
            BaseContext.setCurrentId(empId);
            filterChain.doFilter(request, response);
            return;
        }

        //判断用户是否登录（front)
        if(request.getSession().getAttribute("user") != null){
            log.info("用户已登录，用户id为：{}",request.getSession().getAttribute("user"));
            Long userId = (Long)request.getSession().getAttribute("user");
            BaseContext.setCurrentId(userId);
            filterChain.doFilter(request,response);
            return;
        }

        //未登陆则返回未登录结果，通过输出流方式向客户端页面响应数据
        log.info("用户未登陆");
        response.getWriter().write(JSON.toJSONString(Result.error("NOTLOGIN")));
        return;
    }

    /**
     * 路径匹配，检查本次请求是否需要放行
     * @param urls
     * @param requestURI
     * @return
     */
    public boolean check(String[] urls,String requestURI){
        for(String url:urls){
            boolean match = PATH_MATCHER.match(url,requestURI);
            if(match){
                return true;
            }
        }
        return false;
    }

}
